The distinction of becoming the Dolphins’ No. 1 cornerback is hardly a big deal for Sean Smith because, well, “I always think I’m the best thing on the field,” he says matter-of-factly.

“It helps me get through the game.”

The Dolphins hope that confidence, sharp work in practice all summer, and a more serious approach will translate to games and that Smith becomes consistently good.

“Just looking for a little more consistency, a little more playmaking,” coach Joe Philbin said Friday of Smith.

Linebacker Karlos Dansby calls Smith the team’s most improved player on defense: “The dedication to his craft is starting to show.”

The good news is Smith and the Dolphins’ other defensive backs will not be facing a receiver on the elite level of Houston’s Andre Johnson — who victimized several Dolphins defensive backs last Sunday — until Miami plays Arizona’s Larry Fitzgerald on Sept. 30.

But Sunday presents a formidable challenge: Oakland’s speedy tandem of Darrius Heyward-Bey and Denarius Moore, whose snaps reportedly will be limited somewhat because of a hamstring injury.

Top corner

The Dolphins believe Smith already had become their top cornerback even before Vontae Davis was shipped to Indianapolis. Still, they opted to use him only at times against Johnson.

In the opener, Smith impeded Johnson enough on one play that he couldn’t make a catch. He also deftly knocked away a pass to Arian Foster.

Smith ended up allowing four receptions on the seven balls thrown against him, for a modest 41 yards, including Johnson’s 14-yard catch in the corner of the end zone, just seven seconds before halftime.

Coaches were furious about that play because it extended Houston’s lead to 24-3, and everyone knew Matt Schaub was going to throw it into the end zone.

But overall, coach Joe Philbin likes what he has seen.

“He’s progressing nicely as a player,” Philbin said. “You love some of the physical attributes Sean possesses. He’s got great length, size [6-3]. Has the speed to match up. Sometimes, there are players in this league who can simply out-jump or have greater length, but he’s a guy that can combat that with his own length. His awareness as a player is developing.”

The question is whether that will result in more takeaways. Smith had two interceptions in his final six appearances last season after corralling one pick in his first 44 NFL games.

“There are still some plays down the field on the ball we want to see him make,” Philbin said. “A couple of interceptions, takeaways, that would be the next step in his progression. He has shown signs of playing more physical and tackling better. A takeaway here or there would be great.”

As Smith approaches unrestricted free agency, a big year with interceptions could add millions to his contract next spring. The Dolphins have indicated they want to re-sign him, but the sides have not entered negotiations.

“First couple years, you think you know everything, but you don’t really have it figured out,” Smith said. “This year, I realize not only what it takes to be a professional, but a champion.”

Serious approach

One key, Smith said, is “when we step on the practice field this year, I’m toned it down on jokes during individual work. I have always been a fun guy, loose out there. I’m taking it on the field more seriously.

“When it’s time to lock in during practice, I make sure I get myself and others around me locked in. It’s my fourth year, and it’s a young group. With my personality, it’s easy for guys to do what I do. If I’m joking around, guys around me are going to do it as well.”

Receiver Marlon Moore has noticed the difference: “He’s more technique conscious now, tells me what I do wrong. Now it’s really detailed.”

Said receiver Davone Bess: “You can just see the growth in him from a technique standpoint.”

Smith admits wistfulness that he and good buddy Davis are no longer teammates, though he very much respects new starting cornerback Richard Marshall, who committed pass interference on one play Sunday and allowed four of six passes thrown against him to be completed, for 40 yards.

“I talk to Vontae a lot,” Smith said. “We always had a vision to play here for 15 years, but it doesn’t always work out the way you want it to. I wouldn’t be surprised if he goes to the Pro Bowl this year.”

The Dolphins are banking on Smith having a better chance of someday getting there than Davis.